May need to go through and check your batteries individually.. If you are reading 2.34v across the positive terminals? That is far too much, you have a high resistance connection if that is the case, or a bad cable. Voltage drop across like terminals tells you if you have a high resistance issue.. I would pull all the cables back off and check each battery voltage. You should check this when you put your bank together.
Check out my videos of my battery install:
Checking batteries before connecting:
https://youtu.be/Q5YeBmqMuS4
Checking batteries after connected:
https://youtu.be/H-mFhEYN6xw
I have a few more on my youtube for the batteries.. it was before I had a way to combine multiple videos, so I have a bunch of short videos.. I need to combine them into one video and upload it. Hope these help.